Headbox with torsion beam support



A 1967 F. J. GEDEMER ETAL. 3,334,011

HEADBOX WITH TORSION BEAM SUPPORT Filed Dec. 18, 1964 United States Patent M 3,334,011 HEADBOX WITH TORSION BEAM SUPPORT Fred J. Gedemer and George E. Reynolds, Appleton, Wis., assignors to Allis-Chalmers Manufacturing Company, Milwaukee, Wis.

Filed Dec. 18, 1964, Ser. No. 419,447 Claims. (Cl. 162-347) This invention relates to the construction of a headbox for spreading dilute paper stock across the entire width of a paper web former and in particularly to a construction that may be applied with particular advantage to a secondary headbox making a second deposit of stock on the web former.

In order to produce at high speed'a web of paper having uniform character across its entire width, the dilute stock is carefully discharged from a slice opening across the front and at the bottom of the headbox. The slice opening is defined by an upper lip and a lower lip, each extending across the entire width of the headbox. The upper lip is usually connected to and a part of the front Wall structure of the headbox and the lower lip is usually connected to and is a part of the bottom structure of the headbox. The weight of the stock within the headboxis carried by the bottom structure and tends to cause the bottom structure, including the lower lip of the slice opening, to deflect downwardly. Such deflection makes it necessary to adjust the upper lip to maintain the desired discharge. A very wide headbox, which for example may be over two hundred inches wide, would tend to deflect to an undesirable extent. Such deflection is a function of the weight supported times the third exponential power of the span of bottom structure between supports. The problem related to adjusting the slice to accommodate such deflection is therefore an important consideration in the design of headbox because such deflection increases as the cube of increased width of the headbox.

It is an object of the present invention to provide a bead-box with a new and improved bottom structure having supports dividing the entire width of the headbox into a plurality of shorter spans.

It is also an object of the present invention to provide a headbox with a new and improved bottom structure having supports intermediate the side walls of the headbox and subtended from above, to provide a construction having particular advantage when applied as a secondary headbox.

A further object of the present invention is to provide for adjusting such subtended supports to adjust the deflection of the bottom structure and the attached lower lip of the slice opening.

According to a preferred embodiment of the present invention a plurality of ribs are attached to the top side of a headbox bottom. The ribs are arranged parallel to the headbox side walls, and are equally spaced from each other and the side walls. A torsion beamextends transversely through the headbox and is journaled for support by and for rotation with respect to both side walls of the headbox. The beam passes through each of the ribs and certain of the ribs (identified in description of structures shown in the drawing) are rigidly attached to the beam, as for example, by welds. A lever arm is rigidly secured to each end of the beam projecting outwardly of the headbox. A rod is connected to the free end of each arm and projects upwardly through structure which is part of the headbox shell assembly. A threaded nut is turned on to a correspondingly threaded end portion of each rod projecting through such structure. Turning the nuts to raise the rods therefore turns the arms and twists the torsion beam to apply upwardly directed forces to the forward .end of each rib, thereby resisting downward deflection of the headbox bottom.

Patented Aug. 1, 1967 Other features and objects of the invention that have been attained will appear from the following more detailed description of the invention with reference to the accompanying drawing, in which:

FIG. 1 is a sectional view of the forward part of a headbox according to the present invention;

FIG. 2 is a sectional view of the apparatus shown in FIG. 1, along line IIII and viewed in the direction indicated by arrows;

FIG. 3 is an enlarged perspective view of a calibrated adjusting nut; and

FIG. 4 is a view similar to FIG. 2 showing another embodiment of the present invention.

Referring to FIGS. 1 and 2 of the drawings, a headbox is shown having bottom structure 10, side walls 11, 12 and front wall structure 13. The front wall structure 13 includes a vertical wall section 14 and inclined wall section 15. A horizontal shelf 16 projects forward of wall section 14 and may be part of other assemblies (not shown) forward of wall 14. The shelf 16 extends outwardly of both side walls 11, 12 as shown in FIG. 2. A stock discharge slice 17 is provided by a lower lip 18 projecting forwardly of bottom structure 10, and an upper lip 19 pivotally connected to and subtended from the lower edge of wall section 15. The upper lip 19 may be provided with a blade 20 along its lower edge to provide a substantially vertical knife edge along the inner surface of the upper lip assembly at the slice Opening 17.

The bottom structure 10 includes plates 22, 22a and a plurality of ribs 23 between plates 22, 22a with the ribs 23 being attached to the top surface plate 22 forward of a torsion beam 30 (described later) by welds 24. The ribs 23 are arranged to be parallel to each other and to side walls 11 and 12. Ribs 23 may also be equally spaced from side walls 11, 12 and each other. Ribs 23' are fastened to the beam 30 and divide the width of bottom plate 22 into three equal spans identified by'the characters a, b

and c in FIG. 2.

The torsion beam 30 projects transversely through both side walls 11 and 12 and is journaled therein to retate relative to walls 11, 12. The beam 30 passes through each of the ribs 23 and the ribs are secured to the beam by the welds 31. A lever arm 33 is rigidly secured to each end of beam 30 projecting outwardly of walls 11, 12. An actuating rod 34 is connected to the free end of each arm 33. Each of the rods 34 project upwardly through the shelf 16. An adjusting nut 35 is turned on to a threaded ortion of rod 34 projecting upwardly of shelf 16. FIG. 3 is a more detailed view of adjusting nut 35 and shows a collar 36 projecting upwardly of nut 35, and numerical scales are provided on the top surface of collar 36 and the shank of rod 34 for calibrating the adjustment provided by turn 'ing nut 35 relative to rod 34.

' In the operation of a headbox described with reference to FIGS. 1-3, the weight of the column of paper stock carried by bottom structure 10 tends to cause plates 22, 22a and lower lip 18 to deflect downwardly. It has been determined that this downward deflection can be calculated as being equal to 5 WL /348EI when W=the weight in pounds of stock carried by a span; L=the distance in inches between the structures supporting each end of a span; E=modulus of elasticity of material; and I=moment of inertia of the structure. As shown in FIG. 2, two ribs 23, fastened to beam 30 divide the overall width of bottom structure 10 into three spans a, b and 0, each having one third the width of bottom structure 10. Each span a, b and c will therefore deflect only as much as would the bottom structure without ribs 23' fastened to beam 30 because the distance factor L in the calculation is a factor effective as its cube (i.e., third exponential power). In order that ribs 23' actually provide the function of dividing the effective width of bottom structure 10 into spans one third as wide as overall width, ribs 23 must carry load rather than adding to the load carried by bottom structure 10. This desired result is attained by turning adjusting nuts 35 to raise rods 34 and turn arms 33 counterclockwise, as viewed in FIG. 1. This motion will twist beam 30 and attached ribs 23 counterclockwise to apply a lifting force to the forward ends of ribs 23' and thus the ribs carry load applied to bottom structure 10 along its edge that defines'lower lip 18. Since this support is provided without any added structure beneath bottom structure 10, the headbox is ideally suited for application as a secondary headbox.

The deflection of bottom structure 10 can be still further reduced by the embodiment of the invention shown in FIG. 4. In FIG. 4 ribs 23 and 23 are each fastened to torsion beam structures (that will be described) and the overall width of bottom structure 10 is divided into five spans x, a, b, c, y. These five spans, when supported according to this invention, will deflect only A as much as would bottom structure 10 without such support. That is, each span is only /5 the width of bottom structure and this factor in the aforementioned formula is cubed and therefore becomes the fraction The number of such spans may be any desired number as it depends only on the number of ribs fastened to torsion beam structures such as will now be described.

In order to have the four ribs 23 and 23 shown in FIG. 4 carry load, a hollow torsion beam 39 is journalled over each end of beam 30 to rotate relative to beam 30 and walls 11, 12. The beams 39 are operated in the same manner as beam 30, that is, an arm 40 is connected to a rod 41 that projects upwardly through shelf 16. A nut 42 engages and adjusts the vertical position of each rod 41 to turn each arm 40 and twist the beams 39 to lift ribs 23 to carry load. Turning the nuts 35 to twist beam 30 in the manner previously described results in ribs 23 carrying load. Each of the five spans then are supported according to this invention.

The present invention, therefore, in both of the disclosed embodiments as well as other embodiments that will occur to those skilled in this art, provides a unique headbox that accomplishes the objects of the invention. Such other embodiments and equivalents of the disclosed features of this invention are intended to be included within the scope of this invention. The scope of this invention is therefore intended to be limited only by the scope of the claims such as are, or may hereafter be, appended hereto.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A headbox for a paper making machine and the like comprising: a shell structure forming a box having a bottom structure, a front wall structure and a pair of side walls defining a stock discharge slice opening; a torsion beam journaled in said side walls for rotation relative thereto and projecting through and outwardly of both said side walls; at least one support rib transverse to said front wall structure and attached to said bottom structure forward of said beam; said beam being arranged parallel to said front wall structure and rigidly connected to said rib at a predetermined distance to the rear of the forward end of said rib; and operating means attached to said beam for twisting said beam about the central axis of said beam to adjust the support provided said bottom structure by said beam and said support rib.

2. A headbox for a paper making machine comprising: a shell structure forming a box having a bottom structure, a front wall structure and a pair of side walls defining a stock discharge slice opening; a torsion beam journaled in said side walls for rotation relative thereto and projecting through and outwardly of both said side walls; at least one support rib transverse to said front wall structure and attached to said bottom structure forward of said beam;

said beam being arranged parallel to said front wall structure and rigid-1y connected to said rib at a predetermined distance to the rear of the forward end of said rib; a lever arm rigidly attached perpendicularly to said beam; an actuating rod connected to said arm at a location spaced from said beam and projecting through said shell structure and a surface external of said box; and an adjuster engaging said external surface and said rod for moving said rod in both directions along the axis of said rod and relative to said external surface to thereby turn said arm and twist said beam about the central axis of said beam to adjust the support provided said bottom structure by said beam and said support rib.

3. A headbox for a paper machine comprising: a shell structure forming a box having a bottom structure, a front wall structure and a pair of side walls defining a stock discharge slice opening; a torsion beam journaled in said side walls for rotation relative thereto and projecting through and outwardly of both said side walls; at least one support rib transverse to said front wall structure and attached to said bottom structure forward of said beam; said beam being arranged parallel to said front wall structure and rigidly connected to said rib at a predetermined distance to the rear of the forward end of said rib; a lever arm rigidly attached perpendicularly to said beam; an actuating rod connected to said arm at a location spaced from said beam and projecting through said shell structure and a surface external of said box; and a threaded calibrated adjuster engaging said external surface and a threaded calibrated portion of said rod for moving said rod in both directions along the axis of said rod and relative to said external surface to thereby turn said arm and twist said beam about the central axis of said beam to adjust the support provided said bottom structure by said beam and said support rib.

4. A headbox for a paper making machine comprising: a shell structure forming a box having a bottom structure, a front wall structure having a horizontal shelf projecting forward and transversely of the box and a pair of side walls coacting with said bottom structure and said front wall structure to define a stock discharge slice opening; a torsion beam journaled in said side walls for rotation relative thereto and projecting through and outwardly of both said side walls, at least one support rib within said bottom structure transverse to said front wall structure and attached to said bottom structure forward of said beam; said beam being arranged parallel to said front wall structure and rigidly connected to said rib at a predetermined distance to the rear of the forward end of said rib; a forwardly extending lever arm rigidly attached perpendicularly to said beam; an upwardly projecting actuating rod connected to said arm at a location spaced from. said beam and projecting upwardly through said shelf; and an adjuster engaging said shelf and a portion of said rod for moving said rod in both directions along the axis of said rod and relative to said shelf to thereby turn said arm and twist said beam about the central axis of said beam to adjust the support provided said bottom structure by said beam and said support rib.

5. A headbox for a paper making machine comprising: a shell structure forming a box having a bottom structure, a front wall structure having a horizontal shelf projecting forward and transversely of the box and a pair of side walls coacting with said bottom structure and said front wall structure to define a stock discharge slice opening; a torsion beam journaled in said side walls for rotation relative thereto and projecting through and outwardly of both said side walls; at least one support rib within said bottom structure transverse to said front wall structure and attached to said bottom structure forward of said beam; said beam being arranged parallel to said front wall structure and rigidly connected to said rib at a predetermined distance to the rear of the forward end of said rib; a forwardly extending lever anm rigidly attached perpendicularly to said beam; an upwardly proshelf to thereby turn said arm and twist said beam about the central axis of said beam to adjust the support provided said bottom structure by said beam and said support rib.

6. A headbox for a paper making machine comprising: a shell structure forming a box having a bottom structure, a front wall structure and a pair of side walls defining a stock discharge slice opening; a first torsion beam journaled in said side walls for rotation relative thereto and projecting through and outwardly of both said side walls; at least one support rib connected to said bottom structure forward of said beam and located centrally between and parallel to said side walls; at least one additional rib between each side wall and said centrally located rib parallel thereto and also attached to said bottom structure forward of said beam; said first beam being arranged parallel to said front wall structure and rigidly connected to said centrally located rib at a predetermined distance to the rear of the forward end of said rib; a cylindrical beam journaled in each side wall and over each end of said first beam for rotation relative to said walls and said first beam, each cylindrical beam being rigidly connected to one of said additional ribs; a lever arm rigidly attached perpendicularly to each said beam; an actuating rod connected to each said arm at a location spaced from said beam and projecting through said shell structure and a surface external of said box; and for each rod an adjuster engaging said external surface and said rod for moving said rods in both directions along the axis of said rods and relative to said external surface to thereby turn said arms and twist said beams about the central axis of said beams to adjust the support provided said bottom structure by said beams and said support ribs.

7. A headbox for a paper making machine comprising: a shell structure forming a box having a bottom structure, a front wall structure and a pair of side walls defining a stock discharge slice opening; a first torsion beam journaled in said side walls for rotation relative thereto and projecting through and outwardly of both said side walls; a first plurality of support ribs parallel to said side walls and attached to said bottom structure forward of said beam; at least one additional rib between each side wall and said first plurality of ribs parallel thereto and also attached to said bottom structure forward of said beam; said first beam being arranged parallel to said front wall structure and rigidly connected to each of said first plurality of ribs at a predetermined distance to the rear of the forward end of said ribs; a cylindrical beam journaled in each side wall and over each end of said first beam for rotation relative to said walls and said first beam, each cylindrical beam being rigidly connected to one of said additional ribs and projecting through an adjacent of said side walls; a lever arm rigidly attached perpendicularly to each said beam; an actuating rod connected to each said arm at a location spaced from said beams and projecting through said shell structure and a surface external of said box; and for each rod an adjuster engaging said external surface and said rod for moving said rods in both directions along the axis of said rods and relative to said external surface to thereby turn said arms and twist said beams about the central axis of said beams to adjust the support provided said bottom structure by said beams and said support ribs.

8. A paper stock containing a headbox for a paper making machine comprising: a shell structure forming a box having a bottom structure, a front wall structure having a horizontal shelf projecting forward and trans versely of the box and a pair of side walls coacting with said bottom structure and said front wall structure to define a stock discharge slice opening; a first torsion beam journaled in said side walls for rotation relative thereto and projecting through and outwardly of both said side walls, a first plurality of support ribs parallel to said side walls and attached to said bottom structure forward of said beam; at least one additional rib between each side wall and said first plurality of ribs parallel thereto and also attached to the top of said bottom structure; said first beam being arranged parallel to said front wall structure and rigidly connected to said first plurality of ribs at a predetermined distance to the rear of the forward end of said ribs; a cylindrical beam journaled in each side wall and over each end of said first beam for rotation relative to said walls and said first beam, each cylindrical beam being rigidly connected to one of said additional ribs and projecting through an adjacent of said side walls; a forwardly extending lever arm rigidly attached perpendicularly to the outwardly projecting end of each beam; an upwardly projecting actuating rod connected to each said arm at a location spaced from said beams and projecting upwardly through said shelf; and for each rod an adjuster engaging said shelf and a portion of each said rod for moving said rods in both directions along the axis of said rods and relative to said shelf to thereby turn said arms and twist said beams about the central axis of said beams to adjust the support provided said bottom structure by said beams and said support ribs.

9. A paper stock containing a headbox for a paper making machine comprising: a shell structure forming a box having a bottom structure, a front wall structure having a horizontal shelf projecting forward and transversely of the box and a pair of side walls coacting with said bottom structure and said front wall structure to define a stock discharge slice opening; a first torsion beam journaled in said side walls for rotation relative thereto and projecting through and outwardly of both said side walls; a first plurality of support ribs parallel to said side walls and attached to said bottom structure forward of said beam; at least one additional rib between each side wall and said first plurality of ribs parallel thereto and also attached to the top of said bottom structure; said first beam being arranged parallel to said front Wall structure and rigidly connected to said first plurality of ribs at a predetermined distance to the rear of the forward end of said ribs; a cylindrical beam journaled in each side wall and over each end of said first beam for rotation relative to said walls and said first beam, each cylindrical beam being rigidly connected to one of said additional ribs and projecting through an adjacent of said side walls; a forwardly extending lever arm rigidly attached perpendicularly to the outwardly projecting end of each beam; an upwardly projecting actuating rod connected to each said arm at a location spaced from said beams and projecting upwardly through said shelf; and for each rod a threaded nut engaging said shelf and a threaded portion of each said rod for moving said rods in both directions along the axis of said rods and relative to said shelf to thereby turn said arms and twist said beams about the central axis of said beams to adjust the support provided said bottom structure by said beams and said support ribs.

10. A paper stock containing a headbox for a paper making machine comprising: a shell structure forming a box having a bottom structure, a front wall structure having a horizontal shelf projecting forwardly and transversely of the box and a pair of side walls coacting with said bottom structure and said front wall structure to define a stock discharge slice opening; a first torsion beam journaled in said side Walls for rotation relative thereto and projecting through and outwardly of both said side walls; a first plurality of support ribs within said bottom structure parallel to said side walls and attached to said bottom structure forward of said beam; at least one additional rib between said side wall and said first plurality of ribs parallel thereto and also attached to the top of said bottom structure; said first beam being arranged parallel to said front wall structure and rigidly connected to said first plurality of ribs at a predetermined distance to the rear of the forward end of said ribs; a cylindrical beam journaled in each side wall and over each end of said first beam for rotation relative to said walls and said first beam, each cylindrical beam being rigidly connected to one of said additional ribs and projecting through an adjacent of said side walls; a forwardly extending lever arm rigidly attached perpendicularly to the outwardly projecting end of each beam; an upwardly projecting actuating rod connected to each said arm at a location spaced from said beams and projecting upwardly through said shelf; and for each rod a threaded calibrated nut engaging said shelf and a threaded calibrated portion ofveach said rod for moving said rods in both directions along the axis of said rods and relative to said shelfv to thereby turn said arms and twist said beams about the central axis of said beams to adjust the support provided said bottom structure by said beams and said support ribs.

References Cited UNITED STATES PATENTS 1,909,150 5/1933 Bell-Irving et a1. 162-347 X 2,934,140 4/1960 Goodwillie 162347 X 3,016,089 1/1962 Webster 162-347 X UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,334,011 August 1, 1967 Fred J. Gedemer et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 61, for "SWEZ348EI" read SWL /384EI column 4, line 14, after "paper" insert making Signed and sealed this 16th day of July 1968.

(SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer 

1. A HEADBOX FOR A PAPER MAKING MACHINE AND THE LIKE COMPRISING: A SHELL STRUCTURE FORMING A BOX HAVING A BOTTOM STRUCTURE, A FRONT WALL STRUCTURE AND A PAIR OF SIDE WALLS DEFINING A STOCK DISCHARGE SLICE OPENING; A TORSION BEAM JOURNALED IN SAID SIDE WALLS FOR ROTATION RELATIVE THERETO AND PROJECTING THROUGH AND OUTWARDLY OF BOTH SAID SIDE WALLS; AT LEAST ONE SUPPORT RIB TRANSVERSE TO SAID FRONT WALL STRUCTURE AND ATTACHED TO SAID BOTTOM STRUCTURE FORWARD OF SAID BEAM; SAID BEAM BEING ARRANGED PARALLEL TO SAID FRONT WALL STRUCTURE AND RIGIDLY CONNECTED TO SAID RIB AT A PREDETERMINED DISTANCE TO THE REAR OF THE FORWARD END OF SAID RIB; AND OPERATING MEANS ATTACHED TO SAID BEAM FOR TWISTING SAID BEAM ABOUT THE CENTRAL AXIS OF SAID BEAM TO ADJUST THE SUPPORT PROVIDED SAID BOTTOM STRUCTURE BY SAID BEAM AND SAID SUPPORT RIB. 